Contracts-In-Process And Long-Term Receivables (Narrative) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Contracts-In-Process And Long-Term Receivables [Abstract]
Allowance for doubtful accounts receivable	$ 0.2	$ 0.2
Billed receivables excluding billed orbital receivables	124.1	104.5
Billed orbital receivables	3.3	3.5
Orbital receivables for satellites under construction	140.7	141.5
Unbilled receivables other than orbital receivables	$ 58.5	$ 40.0